According to the state of the art, each deep-drawing mold support is provided with its own stretch piston support, the stretch piston of which presses the cover stretched on the deep-drawing mold into the deep-drawing mold prior to the back-foaming operation. In other words, the number of stretch pistons in the installation equals the number of deep-drawing molds on the round table. This state of the art is illustrated in the attached FIG. 1, in which the rotatable round table, on which deep-drawing molds 12a and 12b have been disposed, has been assigned reference numeral 10. Each deep-drawing mold 12a and 12b is provided with its own stretch piston 14a, 14b, carried by the round table, by means of which a cover stretched on the deep-drawing mold 12a, 12b is pressed into the deep-drawing mold prior to the back-foaming operation. The reference numerals 16a and 16b designate the upper parts of the mold, by means of which the deep-drawing molds 12a and 12b are closed prior to back-foaming, which is performed at a special work station disposed stationary next to the round table 10 and which is being cyclically passed by the separate work stations 12a and 12b. Supports for the stretch pistons 14a and 14b are designated by 18a and 18b.
If, for example, fourteen deep-drawing molds 12a . . . are provided, the state of the art requires the provision of fourteen stretch pistons 14a . . .